Reaction cycle characteristics, common

The complexity of the catalytic reaction is a common thread through most of the chapters that follow. We describe the issues associated with the different time and length scales that underpin the chemical events that constitute a catalytic system. For example, a typical time scale for the overall catalytic reaction is a second with characteristic length scales that are on the order of 0.1 micron. The time scales for the fundamental adsorption, desorption, diffusion and surface reaction steps that comprise the overall catalytic cycle, however, are often 10 sec or shorter. The time scales associated with the movement of atoms, such as that which must occur for surface reconstruction events, may be on the order of a nanosecond. The vibrational frequencies for adsorbed surface intermediates occur at time scales on the order of a few picoseconds. The different processes that occur at these time scales obey different physical laws and, hence, require different methods in order to calculate their influence on reactivity. In this book we will show how the... 

Chemoautotrophs are microbes which obtain energy by catalyzing an exergonic chemical reaction (commonly at interfaces between aerobic and anaerobic environments) and which produce biomass by fixing inorganic carbon. Nitrosomonas europea oxidizes ammonia and uses rubisco and the Calvin Cycle to fix carbon (the most common sulfide-oxidizing organisms also use the Calvin Cycle). Its isotopic characteristics could therefore, be expected to be similar to those of other aerobic, prokaryotic autotrophs such as Synechocystis. As shown in Table 5, this expectation is fulfilled. 

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